Nowadays, the task of harvester heads used in forestry machines is to fell a tree, strip the branches from it, and cut the tree into suitable lengths. In addition, the harvester head can have other additional tasks. To strip the branches from a tree, the harvester head includes stripping blades, which press around the trunk of the tree. With the aid of a transfer device, the tree is moved in its longitudinal direction through the harvester head, so that the stripping blades strike the branches and strip them off the trunk. In the present application, the term forestry machine also refers to devices used as processors, which are on the ground or otherwise supported, and are used to process trees that have been already felled.
Freedom from maintenance is one of the most important properties in terms of the work efficiency of a harvester head. One factor affecting this property is the durability of the stripping blades. Publication U.S. Pat. No. 8,002,004 B2 discloses a solution according to the prior art, in which the stripping blades are manufactured by welding from steel with a high strength and hardness. However, welding weakens the fatigue resistance of the stripping blade and the hardness of the blade. In addition, the dimensional precision of a welded stripping blade is poor when the welded points warp and cause stresses in the stripping blade. In addition, the strong and hard manufacturing material interferes with the sharpening of the blade. In addition, the welded construction is expensive and slow to manufacture.
Further, a drawback in known solutions has been their weight, attempts having been made to reduce this as much as possible. At the same time, however, the durability of the structure, which suffers from the lightening of the materials, becomes a barrier. In addition, separate brackets must be made for the hoses of, for example, colour-marking or other accessories, which would otherwise be exposed to possible damage.